UPDATE (8/27): A Canadian court has declined to issue a stay to prevent the vents survey from continuing. The ship is en route to the area, and will continue with the planned research project; the first step will be laying bottom-mounted receivers, before commencing ten days of seismic airgun operations during September. In the course of the short legal brouhaha, it came out that the Canadian Department of Foreign Affairs had essentially lost Columbia University’s application for Foreign Ship clearance from February until mid-July, thus contributing to the lack of time for all concerned parties to respond to the plans prior to these hectic pre-cruise days. An amended permit application from Columbia, submitted the day after the initial lawsuit was filed, was accepted by the Canadian Department of Fisheries and Oceans; it aims to avoid exposing any whales to more than 160dB of sound, which creates an effective “exclusion zone” of nearly 7km. This seems quite surprising, as only last May I participated in a DFO seismic mitigation expert committee meeting at which the oil and gas industry and agency staff seemed fully content with 500m exclusion zones, except in especially rich and sensitive whale habitat, where the most extensive exclusion zones were, as I recall, 2.5km. What sorts of magical powers will be employed Marine Mammal Observers aboard the Langseth to effectively observe at this super-human distance, was not detailed by the DFO. In any case, the relative lack of whales in this region this time of year should assure that few if any whales are close enough to be harmed, though some may well hear and avoid it; various species seem to avoid seismic sounds at different distances, from a km or so for some species to 30km for belugas and bowhead whales (neither of which occur in this region). Recent news reports can be read here and here.

A month-long seismic survey long scheduled to begin this week has been temporarily sidelined by a Canadian court challenge mounted by BC-based EcoJustice. While the Acoustic Ecology Institute has been closely monitoring the effects of seismic surveys for several years, and I do indeed have concerns about the degree to which airgun noise may disrupt foraging in some cetaceans, this particular lawsuit appears to me to be a dramatic over-reaction to what is planned. Throwing up legal roadblocks to a carefully designed, ten-day academic study is a very extreme reaction, and should be reserved for times and places where there is real danger of harm. But for this survey, the risks are truly negligible—and this is spoken by someone who resents the free use of “negligible impact” in EAs that minimize the effects of chronic behavioral disruption of cetaceans by noise.

The survey, to be run by Columbia University’s Lamont-Doherty Earth Observatory and researchers from the University of Oregon, aims to study the geology underlying a deep benthic vent community 250 km offshore from Vancouver Island, as well as the larger tectonic plate structure in this earthquake-prone region. The lawsuit seeks a restraining order, contending that Canada’s Minister of Foreign Affairs cannot grant clearance to a foreign vessel that is expected to harass marine mammals in violation of Canadian law. “To ensure compliance with environmental laws, Canada should deny clearance to this vessel and refuse to sanction the harassment of endangered whales” say Lara Tessaro, Ecojustice lawyer. (I can’t speak to EcoJustice’s point re: Canadian regulatory process, but the whale threat is being wildly overblown; see below) The R.V. Langseth would be outfitted with 36 airguns, which fire together to create a loud impulse sound, with its echoes from deep beneath the seafloor to be recorded by bottom-mounted receivers deployed from 4-10km apart. The researchers completed an Environmental Assessment and received permits from NMFS, in accordance with US law governing research funded by the US National Science Foundation (see EA with project summary and projected whale encounters).

The EA projects that the survey could encounter a few whales in the area, which was designated as an MPA in order to protect the still little-studied communities of invertebrates around the hot vents. Up to 9 minke whales, 12 fin whales, 26 sperm whales, and 3 blue whales, along with several hundred of the regions many thousands of dolphins are expected to hear sounds of 160dB or more, enough to likely make them move away; these exposures will occur at ranges of 4-8km. No injuries are expected, as both visual and passive acoustic monitoring will aim to power down the airguns if any animals approach the safety zone of 700-1200m. While the survey will continue at night and in poor visibility—a sore point with many environmentalists—at least one airgun will continue to fire, in an effort to let animals know they are nearby, so they can move away if needed. In addition, the survey was planned for a time of year when fewer whales are in the region (most of the large baleen whales are still in summer feeding grounds further north). The LDEO seismic survey team is among the most precautionary of the survey operators (far moreso than the hundreds of oil and gas surveys that take place yearly), and in particular will be monitoring all whale activity in the area around the ship, to gather more data on the various behavioral responses to airguns that are seen—by contrast, industry surveys routinely claim to be unable to spare the extra time and effort to do any more than assure whales are outside the safety zone. In addition, the survey will be “shooting” its airguns only once every 3-4 minutes, as compared to once every 10 to 20 seconds as in industry surveys); this is yet another measure of the project planners working to reduce their soundprint in the area, shooting enough to get the data they need but avoiding acoustic overkill.

Resistance to this survey centers on the fact that it’s taking place in and around the Endeavor Hydrothermal Vents MPA, with an emphasis on the potential to deafen whales. While it would be very interesting to have some Autonomous Underwater Vehicles shooting video on the seafloor during the surveys, to see whether the seafloor creatures respond to the airgun sounds, the risk to whales is indeed very very minimal. The MPA in question is a “postage stamp” area centered on the deep vent communities, and has no particular special relevance to whales. The concern being expressed is understandable (“If marine animals can’t find safety in the few areas set aside for them, where will they find it?” says Canadian Parks and Wilderness Society National Oceans Manager Sabine Jessen), but seemingly dramatically overstated: “They have little chance of survival in the long-term without these refuges from human disturbance, she continues.” But, being more realistic, the waters are 2km deep at the vents, and generally 2.5km or more in surround areas being surveyed. This depth should protect the vent communities themselves from extreme airgun sound levels (which are, in fact, not as loud as the extremely common Magnitude 0-2 seaquakes that are centered on the vent region). Airgun shooting is planned for only 10 days, meaning that (barring some freakish coincidence of special biological vulnerability in the benthic community), there is no real chance of risking their survival. I would be interested to hear what the biologists who study this benthic community think about the survey—do they feel it is risky, or a violation of the MPA’s purpose, or do they look forward to learning more about what underlies these still little-understood outposts of earthly life?

[…] species to 30km for belugas and bowhead whales (neither of which occur in this region). Read the earlier AEInews post covering this incident here. Recent news reports can be read here and here. addthis_url = […]

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